SEAL RING

The present invention provides a seal ring that can exhibit a sealing function even when fluid pressure is low. A first elastic body sealing portion 200X is provided between a first front end surface 111Xa on a circumferential direction front end of a first fitting projection 111X and a first opposing surface 112Ya provided on a second fitting recess 112Y so as to oppose the first front end surface 111Xa, whereby the first elastic body sealing portion 200X presses the first front end surface 111Xa and the first opposing surface 112Ya in directions for forcing the first front end surface 111Xa and the first opposing surface 112Ya away from each other in a circumferential direction, and a second elastic body sealing portion 200Y is provided between a second front end surface 111Ya on a circumferential direction front end of a second fitting projection 111Y and a second opposing surface 112Xa provided on a first fitting recess 112X so as to oppose the second front end surface 111Ya, whereby the second elastic body sealing portion 200Y presses the second front end surface 111Ya and the second opposing surface 112Xa in directions for forcing the second front end surface 111Ya and the second opposing surface 112Xa away from each other in the circumferential direction.